Implant and anchor assembly

ABSTRACT

An implant assembly comprising an implant having a load bearing surface with a contour corresponding to a patient&#39;s articular surface, and a bone facing surface including a fixation element, an anchor configured to be secured to bone beneath said patient&#39;s articular surface, said anchor including a second fixation element, and wherein said first fixation element is configured to be secured to said second fixation element.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 61/949,774, filed Mar. 7, 2014; U.S. Provisional Application Ser.No. 61/949,789, filed Mar. 7, 2014; U.S. Provisional Application Ser.No. 61/949,824, filed Mar. 7, 2014; and U.S. Provisional ApplicationSer. No. 61/950,762, filed Mar. 10, 2014, the entire disclosures ofwhich are fully incorporated herein by reference.

FIELD

The present disclosure relates to devices and methods for the repair ofdefects that occur in cartilage on the surface of bone, as well as bone,particularly related to the human shoulder.

BACKGROUND

Articular cartilage, found at the ends of articulating bone in the body,is typically composed of hyaline cartilage, which has many uniqueproperties that allow it to function effectively as a smooth andlubricious load-bearing surface. When injured, however, hyalinecartilage cells are not typically replaced by new hyaline cartilagecells. Healing is dependent upon the occurrence of bleeding from theunderlying bone and formation of scar or reparative cartilage calledfibrocartilage. While similar, fibrocartilage does not possess the sameunique aspects of native hyaline cartilage and tends to be far lessdurable.

In certain instances, an injury may not be limited to the cartilage, butmay also extend into the bone which supports the cartilage. For example,with a shoulder injury, such injury may include a fracture of thescapula and even more particularly a fracture of the glenoid rim to theglenoid cavity.

In some cases, it may be desirable or necessary to repair the damagedarticular cartilage and/or bone using an implant. In instances whereonly cartilage may be damaged, the implant should have a shapesubstantially corresponding to the articular cartilage proximate thearea where the implant is to be placed in order to maximize thepatient's comfort, minimize damage to surrounding areas, and maximizethe functional life of the implant. In instances where bone is damaged,the implant may be increased in size to accommodate the damagedlocation.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the claimed subject matter will be apparentfrom the following detailed description of some example embodimentsconsistent therewith, which description should be considered withreference to the accompanying drawings, wherein:

FIG. 1 is an exploded perspective view of a 3-piece implant assemblycomprising an implant body, implant fixation member and an anchoraccording to one embodiment of the present disclosure;

FIG. 2 is cross-sectional side view of the assembled implant body andimplant fixation member of FIG. 1;

FIG. 3 is a cross-sectional side view of the assembled implant assemblyof FIG. 1;

FIG. 4 is an exploded perspective view of a 2-piece implant assemblycomprising an implant body and an anchor according to another embodimentof the present disclosure;

FIG. 5 is a perspective view of an alternative anchor according to thepresent disclosure;

FIG. 6 is a side view of the anchor of FIG. 5;

FIG. 7 is a cross-sectional side view of the anchor of FIGS. 5 and 6assembled with the implant body of FIG. 4;

FIG. 8 is a perspective view of an alternative anchor according to thepresent disclosure;

FIG. 9 a close-up perspective view of the portion of the anchor of FIG.8 bounded by circle A;

FIG. 10 is a side view of the anchor of FIG. 8;

FIG. 11 is a close-up side view of the anchor of FIG. 10 bounded bycircle B;

FIG. 12 is a cross-sectional side view of the anchor of FIGS. 8-11assembled with an alternative implant body according to the presentdisclosure;

FIG. 13 is a close-up cross-sectional side view of the portion of theanchor and implant body of FIG. 12 bounded by circle C;

FIG. 14 is a is a perspective view of an alternative anchor according tothe present disclosure;

FIG. 15 is a cross-sectional side view of the anchor of FIG. 14assembled with an alternative implant body according to the presentdisclosure;

FIG. 16 is a side view of another two-piece implant assembly accordingto another embodiment of the present disclosure; and

FIG. 17 is a cross-sectional side view of an implant assembly comprisingan implant body and an anchor according to another embodiment of thepresent disclosure.

DETAILED DESCRIPTION

Generally, the present disclosure may feature systems, devices, andmethod for forming an implant assembly. For example, the implantassembly may include an implant configured to be coupled to an elongatedfirst anchor by way of a first and a second fixation element,respectively. The connection between the implant and the anchor may beconfigured to inhibit separation and/or rotation of the componentsrelative to one another. The connection formed between the componentsmay particularly be a frictional connection and/or a mechanicalconnection.

The implant and the anchor may be formed from different materials. Forexample, the implant may be formed of a plastic composition and/or ametal composition and the anchor may be formed of a plastic compositionand/or a metal composition. In an embodiment in which the implant andthe anchor are made from different materials, the implant may include animplant fixation member, which may be formed from a material the sameas, or similar to, the material of the anchor. The implant fixationmember may be secured to the implant body in a variety of ways include,but not limited to, snap fit connections, welding, overmolding,adhesives, and/or the like. The implant fixation member may include afirst fixation element configured to form a connection with a secondfixation element of the anchor to securely couple the implant to theanchor.

The implant assembly may be used to repair and/or replace any joint inthe body. For example, the implant assemble may be used to repair and/orreplace a synovial joint implant assembly such as, but not limited to, aball-and-socket joint implant assembly including a shoulder jointimplant assembly, particularly a glenoid implant assembly.

Mechanical connections formed between the components herein may includefriction fit connections (which may also be referred to an interferenceor press fit) and positive mechanical engagement connections. A frictionfit connection may be understood as a connection formed between thecomponents which solely relies upon friction to inhibit separation ofthe components, particularly by one of the components being pressed intothe other component such that at least one of the components iscompressed (deformed) against one another. On the other hand, a positivemechanical engagement connection may be understood as a connectionformed between the components which does not rely solely on friction toinhibit separation of the components and which includes a mechanicalinterlock to inhibit separation of the components (e.g. overlappingsurfaces).

For the implant assemblies herein, in certain applications, a frictionfit connection between the components may offer certain advantages overa positive mechanical engagement, such as where it is particularlydesirable to inhibit rotation of the components relative to one another.In other applications, a positive mechanical engagement connectionbetween the components may offer certain advantages over a friction fitconnection, such as where it is particularly desirable to inhibitseparation of the components relative to one another. In still otherapplications both a friction fit connection and a positive mechanicalengagement connection may be particularly desirable to inhibit rotationand separation of the components relative to one another, respectively.

According to certain embodiments, the implant assembly may replace onlya portion of the articular surface proximate the defect site rather thanthe entire articular surface. As such, the implant assembly may minimizethe amount of the articular surface which is operated on thus allowingmore of the patient's original articular surface to be unaffected andproviding a more physiologically normal joint. However, in otherembodiments, the implant assembly may replace the entire articularsurface. In still other embodiments, the implant assembly may replacethe portion of the bone adjacent (outside) the articular surface, suchas the supporting rim of the joint, such as to repair, for example, aglenoid rim fracture.

Depending on the size of the implant assembly, such may allow forminimally invasive surgery, particularly arthroscopic surgery (which mayalso be referred to as keyhole surgery), which may reduce the amount ofpain and/or discomfort experienced by the patient and may reduce healingtimes. However, while in certain embodiments the implant assembly may beconfigured to replace only a portion of the articular surface proximatethe defect site rather than the entire articular surface, in otherembodiments the implant assembly may be configured to replace the entirearticular surface. For the sake of clarity, the bone and the excisionsite is generally not illustrated.

Referring now to FIGS. 1-3, there is shown an implant assembly 10 aaccording to the present disclosure. Implant assembly 10 a comprises animplant 20 and an elongated first anchor 92. The implant 20 comprises animplant body 22 and an implant fixation member 62.

Implant body 22 may be formed of a plastic composition and may moreparticularly comprise, essentially consist of, or consist of a plasticcomposition. Exemplary plastic compositions may comprise thermoplasticcompositions such as polyether ether ketone (PEEK) and polyethylene(PE), including ultrahigh molecular weight polyethylene (UHMWPE) andhigh density polyethylene (HDPE). In other embodiments, implant body 22may be formed of a metal composition and may more particularly comprise,essentially consist of, or consist of a metal composition. Exemplarymetal compositions may comprise stainless steel, titanium, aluminum,chromium cobalt, and/or any alloy thereof.

Implant 20, and more particularly implant body 22, has a joint facingside including a load bearing (joint articulation) surface 26, which isformed and supported by an articulation support region 27 (FIG. 2) ofthe implant body 22. The load bearing surface 26 may have a contoursubstantially corresponding to or based on the contour of an articularsurface of a patient being repaired. The contour of the load bearingsurface 26 may be based on a plurality of measurements taken at thepatient's articular surface (for example, using a measuring and/ormapping tool as generally described in U.S. Pat. Nos. 6,520,964,6,610,067, 6,679,917, 7,029,479 and 7,510,558, which are fullyincorporated herein by reference) and/or may be based on one or moretemplates.

The load bearing surface 26 may be based on two or more curvatures, forexample, the anterior-posterior curvature and the superior-inferiorcurvature. One or more of the anterior-posterior and/orsuperior-inferior curvatures may themselves be based on multiple curves,(for example, as generally described in U.S. patent application Ser. No.12/027,121, filed Feb. 6, 2008 and entitled System and Method for JointResurface Repair, which is fully incorporated herein by reference). Theload bearing surface 26 may be generally concaved. For example, the loadbearing surface 26 may have a generally hemi-spherical shape. In certainembodiments, the load bearing surface 26 may be a generic (artificial)surface of the glenoid cavity.

The load bearing surface 26 may be surrounded by a beveled surroundingsupport region 28 disposed adjacent the perimeter of the load bearingsurface 26. The beveled surrounding support region 28 may reduce thepotential of further damage to the surrounding articular surface byeliminating a hard transition between the load bearing surface 26 andthe remaining articular surface of the patient. The beveled region 28may be particularly helpful if a portion of the implant assembly 10 a isslightly proud with respect to the remaining articular surface.

The implant 20 also comprises a bone facing surface 30, which is shownto be non-planar and which may substantially correspond to a contour ofan excision site formed in an articular surface of a patient. Moreparticularly, a perimeter of the implant 20 may substantiallycorresponds to a perimeter of an excision site 2 formed in the articularsurface 1 as generally illustrated in FIG. 3. The excision site 2 may beprepared, for example, as generally described in U.S. patent applicationSer. No. 12/762,948, filed February Apr. 19, 2010 and entitled GlenoidResurfacing System and Method, which is fully incorporated herein byreference).

Implant 20 also includes a first fixation element 32 configured toengage with a second fixation element 94 (FIG. 1) of the elongatedanchor 92 as generally illustrated in FIG. 3. In the illustratedembodiment, the first and the second fixation elements 32, 94 areillustrated as a tapered recess and a tapered protrusion configured toform a friction connection therebetween, but it should be appreciatedthat first fixation element 32 may be formed by a tapered protrusion andthat the second fixation element 94 may be formed by a tapered recess.Examples of the first and second fixation elements 32, 94 are alsodescribed in U.S. Pat. Nos. 6,520,964, 6,610,067, 6,679,917, and7,678,151, all of which are fully incorporated herein by reference.Alternatively, fixation elements 32, 94 may include, but are not limitedto, snap-fits, press-fits, threads, or coupling elements.

In the illustrated embodiment, the first fixation element 32 is formedby the implant fixation member 62. The implant fixation member 62 may besecured to the implant body 22 in any manner known to those skilled inthe art. For example, the implant body 22 may include one or morerecesses 44 which extend continuously and/or partially (e.g.,intermittently) round a circumference of an annular fixation ring 42 andthe longitudinal axis of the first anchor LA_(FA) in a direction whichis oriented inward (i.e. transverse to a longitudinal axis of the firstanchor LA_(FA)) as to create one or more undercuts and one or morecorresponding lips 46, which also extend continuously and/or partiallyaround a circumference of the annular fixation ring 42. As shown, withregards to the present embodiment, recess 44 is adjacent an intersectionof the annular fixation ring 42 with the articulation support region 27of the implant body 22, though this is not a limited of the presentdisclosure unless specifically claimed as such.

The implant fixation member 62 may include one or more fastener segments64 configured to be received and generally correspond to the one or morerecesses 44 of the implant body 22. The fastener segments 64 may bedisposed about a perimeter circular edge 66 of the implant fixationmember 62, for example, which abuts the articulation support region 27of the implant body 22. During assembly of implant 20, the one or morefastener segments 64 of the implant fixation member 62 may be snap fitover the lip(s) 46 and into the recess(s) 44 of the implant body 22 toprovide a positive mechanical engagement connection there between.

According to one embodiment, implant fixation member 62 and implant body22 may be assembled by inserting annular fixation ring 42 of the implantbody 22 into annular recess 68 of the implant fixation member 62. Forexample, implant fixation member 62 may line (e.g., cover and/or abutagainst) at least a portion of the sidewall 54 of annular fixation ring42. More particularly, implant fixation member 62 may include asubstantially cylindrical sidewall 72 (also tapered at a taper angle,for example, from 1 to 10 degrees) which is inserted into implantfixation recess 34 formed by annular fixation ring 42 of implant body22. In order to increase the retention strength of implant fixationmember 62 and implant body 22 to one another, the sidewall 72 of theimplant fixation member 62 may form a friction fit connection againstsidewall 54 defining implant fixation recess 34. The annular fixationring 42 may include an arcuate leading end 48 which tapers withincreasing distance away from articulation support region 27 and followssubstantially the same contour as annular recess 68 of the implantfixation member 62. Thereafter, the one or more fastener segments 64 ofthe implant fixation member 62 may be snap fit over the lip 46 and intothe recess 44 of the implant body 22 to provide the positive mechanicalengagement connection there between.

While it has been described how implant fixation member 62 and implantbody 22 may be secured to one another by mechanical connection (e.g.,friction fit connection and/or positive mechanical engagementconnection), implant fixation member 62 and implant body 22 may also besecured to one another by use of an adhesive (e.g. epoxy) there between,welding implant fixation member 62 and implant body 22 to one another,and/or insert injection molding implant fixation member 62 and implantbody 22 to one another. For example, when implant fixation member 62 isformed of metal and implant body 22 is formed of plastic, the implantfixation member 62 may be inserted in an injection mold to form theimplant body 22 and plastic to form the implant body 22 may be moldeddirectly to the backside of the implant fixation member 62.

In certain embodiments, implant fixation member 62 may be formed of aplastic composition and may more particularly comprise, essentiallyconsist of, or consist of a plastic composition. Exemplary plasticcompositions may comprise thermoplastic compositions such as polyetherether ketone (PEEK) and polyethylene (PE) such as ultrahigh molecularweight polyethylene (UHMWPE) and high density polyethylene (HDPE). Inother embodiments, implant fixation member 62 may be formed of a metalcomposition and may more particularly comprise, essentially consist of,or consist of a metal composition. Exemplary metal compositions maycomprise stainless steel, titanium, aluminum, chromium cobalt, and/orany alloy thereof.

The first anchor 92, FIG. 3, is configured to be secured to thepatient's bone 1 within the excision site 2 and includes a proximal endregion 97 and a distal end region 96 as best illustrated in FIG. 1. Asdiscussed herein, the proximal end region 97 includes a second fixationelement 94 configured to be secured to the first fixation element 32 asillustrated in FIG. 3. As discussed herein, the second fixation element94 may include a tapered protrusion. The tapered protrusion may includea sidewall 95 having an outer contour 104 which has a tapered,continuous substantially cylindrical surface 106 that substantiallycorresponds to the tapered surface of the first fixation element 32. Inorder to connect the first anchor 92 to the implant 20, the first andthe second fixation elements 32, 94 may abut against each other to forma friction fit connection. For example, the substantially cylindricalsurface 106 of the second fixation element 94 may contact the sidewall72 of the first fixation element 32.

The first anchor 92 may comprise one or more anchor elements 100configured to engage, connect, and/or secure the anchor 92 with thebone. For example, the anchor elements 100 may include one or moreexternal screw (helical) threads 102 configured to threadably engage andconnect with the bone. It should be appreciated, however, that one ormore of the anchor elements 100 may include ribs, protrusions, barbs, orthe like.

With reference to FIG. 1, proximal end region 97 of the first anchor 92may include a driver receptacle 98 arranged to receive a drive membertherein, particularly to drive the first anchor 92 into bone. Drivereceptacle 98 may include any connection configured to transmit torquebetween a drive member including, but not limited to, a splinedreceptacle, a hex (single or double) drive receptacle, a square (single,double or triple) drive receptacle, a hexalobular drive receptacle, apolydrive (ribe) drive receptacle, a spline (four, six or twelve) drivereceptacle and a pentalobular drive receptacle.

Elongated first anchor 92 may be formed of a plastic composition and maymore particularly comprise, essentially consist of, or consist of aplastic composition. Exemplary plastic compositions may comprisethermoplastic compositions such as polyether ether ketone (PEEK) andpolyethylene (PE) such as ultrahigh molecular weight polyethylene(UHMWPE) and high density polyethylene (HDPE). In other embodiments,first anchor 92 may be formed of a metal composition and may moreparticularly comprise, essentially consist of, or consist of a metalcomposition. Exemplary metal compositions may comprise stainless steel,titanium, aluminum, chromium cobalt, and/or any alloy thereof.

The bone facing surface 30 of implant 20 may further comprise a secondelongated anchor 80, having a longitudinal axis LA_(SA) which extendssubstantially parallel (within 5 degrees) with the first anchorlongitudinal axis LA_(FA). As shown, the second anchor 80 may have acylindrical sidewall 82 with a plurality of barbs 84 which extendcontinuously around a circumference of the second anchor 80.

Implant assembly 10 a may be assembled by first directly connectingimplant fixation member 62 with implant body 22, and thereafterdirecting connecting first anchor 92 with implant 20 using the first andsecond fixation elements 32, 94. To install the implant assembly 10 ainto a patient's bone, an excision site is formed in the bone and firstand second holes may be drilled into bone (e.g. scapula) to receive thefirst anchor 92 and the second anchor 80, respectively. The holes and/orthe excision site may be drilled with one or more guides to ensureproper distance and orientation relative to one another. The implantassembly 10 a may be implanted by first inserting the distal end anchorportion 96 of first anchor 92 into the first hole and rotating (orimpacting) the first anchor 92 with a drive member to engage with andconnect to the bone. Thereafter, the implant body 22 (with the implantfixation member 62 secured thereto) may be properly oriented and thefirst fixation element 32 of the implant fixation member 62 may becoupled to the second fixation element 94 of first anchor 92 to form afriction fit. The second anchor 80 may also be inserted in the seconddrilled bone hole and connected to the bone by a friction fitconnection, particularly by barbs 84 pressing against the bone surfaceof the drilled hole.

Referring now to FIG. 4, there is shown implant assembly 10 b accordingto the present disclosure. In contrast to implant assembly 10 a, implantassembly 10 b eliminates implant fixation member 62. Furthermore, withregards to implant body 22, recess 44 and lip 46 of implant body 22 nolonger extend continuously around the circumference of annular fixationring 42, but rather extend intermittently around the circumference ofthe annular fixation ring 42. As shown, both the recess 44 and the lip46 may be interrupted by a plurality of localized notches 52 which breakthe recess 44 and the lip 46 into a plurality of intermittent segments44 a and 46 a, respectively which extend around a circumference of theannular fixation ring 42. With the elimination of implant fixationmember 62, the recess 44 may provide pockets for bone growth or bonecement therein after the implant body 22 has been implanted to increaseretention strength. Lip 46 may then inhibit the implant body 22 frombeing displaced (pulled) from the bone in the direction of the firstanchor longitudinal axis LA_(FA). The bone may also grow in (and/or thebone cement may flow into) notches 52, which will inhibit the implantbody 22 from rotating around the first anchor longitudinal axis LA_(FA).

As shown by FIG. 4, the outer contour 104 of second fixation element 94may include at least one sidewall fixation feature 108. Moreparticularly, sidewall fixation feature 108 may comprise at least onebarb 110. As shown, the at least one barb 110 comprises a plurality offrusto-conical barb rings 112 which extend continuously around proximalend fixation element 94 and the first anchor longitudinal axis LA_(FA).

In order to connect the first anchor 92 to implant body 22, the barbs110, and more particularly the barb rings 112, may form a friction fitconnection against sidewall 54 of the second fixation element 32 (e.g.,the implant fixation recess 34) of implant body 22. The distal ends(e.g., tips) of the barb rings 112 may be arranged in an overall contoursubstantially corresponding to the taper of the first fixation element32 (e.g., the taper of the sidewall 54 of the first fixation element 32.As such, the anchor 94 may be used with any first fixation element 32having a corresponding taper. For example, a metal anchor 94 may be usedwith a plastic implant 20 and/or a metal implant 20 (e.g., metal implantfixation member 62). In the foregoing manner, the second fixationelement 94 of first anchor 92 mechanically connects with the firstfixation element 32 of the implant body 22.

Referring now to FIGS. 5-6, there is shown another embodiment of firstanchor 92 according to the present disclosure. As shown, the outercontour 104 of proximal second fixation element 94 comprises a pluralityof frusto-conical barb rings 112 which extend intermittently aroundsecond fixation element 94 and the first anchor longitudinal axisLA_(FA). As shown, in contrast to the prior embodiment 10 b, reliefrecesses 114 extend longitudinally through the barb rings 112 formingeach barb ring 112 into a plurality of barb ring segments 116.Furthermore, as shown the barb ring segments 116 of each barb ring 112are laterally offset to one another around the first anchor longitudinalaxis LA_(FA).

Referring now to FIG. 7, for implant assembly 10 c, in order to connectthe first anchor 92 to implant body 22, similar to the prior embodiment10 b, the barbs 110, and more particularly the barb rings 112, form afriction fit connection with the first fixation element 32 (e.g.,against sidewall 54 of implant fixation recess 34 of implant body 22).For example, the barb ring segments 116 of the barb rings 112 form afriction fit connection against sidewall 54 of implant fixation recess34 of implant body 22. In the foregoing manner, the second fixationelement 94 of first anchor 92 mechanically connects with the implantbody 22.

Referring now to FIGS. 8-11, there is shown another embodiment of afirst anchor 92 according to the present disclosure. As shown, the outercontour 104 of second fixation element 94 comprises a plurality offrusto-conical barb rings 112 (FIG. 11) which extends continuouslyaround proximal end fixation element 94 and the first anchorlongitudinal axis LA_(FA).

In addition, the outer contour 104 of second fixation element 94comprises a second different sidewall fixation feature 108 in the formof a plurality of elongated ribs 122 (FIGS. 9 and 11) adjacent theplurality of frusto-conical barb rings 112, which are located betweenthe frusto-conical barb rings 112 and a proximal end 120 of the firstanchor 92. More particularly, the outer contour 104 of second fixationelement 94 comprises a plurality of elongated ribs 122 separated byelongated relief recesses 124, both of which extend longitudinally withthe longitudinal axis. Even more particularly, the plurality ofelongated ribs 122 are substantially parallel (e.g., within 5 degrees)to one another and extend substantially parallel (e.g., within 5degrees) along the first anchor longitudinal axis LA_(FA).

As best shown by FIG. 9, in addition to the elongated ribs 122 beingarranged circumferentially around the outer contour 104 of the sidewall95 of second fixation element 94, the plurality of ribs 122 may bearranged at the proximal end 120 of first anchor 92 which are separatedby semi-circular recesses 126. In various embodiments, the presentdisclosure contemplates any number of elongated ribs 122. The elongatedribs 122 may be uniformly spaced from one another around thecircumference of the second fixation element 94 of first anchor 92.Alternatively, the plurality of elongated ribs 122 may non-uniformlyspaced from one another around the circumference of the second fixationelement 94.

Referring now to FIGS. 12-13, for implant assembly 10 d, in contrast tothe prior embodiments 10 a-10 c, the first fixation element 32 (e.g.,but not limited to, the implant fixation recess 34 of the implant body22) includes at least one sidewall fixation feature 130 which isconfigured to mate and cooperate with the at least one sidewall fixationfeature 108 of second fixation element 94 of first anchor 92 to form apositive mechanical engagement connection against separation of theimplant body 22 from the first anchor 92.

More particularly, as shown, the at least one sidewall fixation feature130 of the first fixation element 32 comprises an (undercut) ridge/step132 in sidewall 54 of the implant fixation recess 34 which mates andcooperates with the ridge/step 118 of barb 110, and more particularlybarb ring 112, to form the positive mechanical engagement. Even moreparticularly, the sidewall 54 of implant fixation recess 34, unlikeprior embodiments 10 a-10 c, includes a frusto-conical surface 134 whichmates and cooperates with frusto-conical barb ring 112. As such, the(undercut) ridge/step 132 in sidewall 54 of implant fixation recess 34may be formed with a frusto-conical surface 134 which extendscontinuously around the sidewall 54 of implant fixation recess 34 andthe first anchor longitudinal axis LA_(FA). For example, the ribs 122form a friction fit connection against sidewall portion 54 of implantfixation recess 34 of implant body 22 when the second fixation element94 of first anchor 92 is fully inserted into implant fixation recess 34of implant body 22. In addition, barb 110 and even more particularlybarb ring 112, engages with the ridge/step 132 of the implant body 22 toform a positive mechanical engagement connection.

Specifically, the ridge/step 118 of barb 110, and more particularly barbring 112, and the ridge/step 132 on the sidewall 54 of implant fixationrecess 34 forms a mechanical interlock against separation of the implantbody 22 from the first anchor 92. In the foregoing manner, the secondfixation element 94 of first anchor 92 mechanically connects with thefirst fixation element 32 of the implant body 22, particularly by afriction fit connection and a positive mechanical engagement connectionwithin implant fixation recess 34.

Referring now to FIG. 14, there is shown another embodiment of a firstanchor 92 according to the present disclosure. As shown, the outercontour 104 of second fixation element 94 comprises at least onesidewall fixation feature 108. More particularly, sidewall fixationfeature 108 comprises at least one projection 140. The at least oneprojection 140 comprises a plurality of projections 140 which extendcontinuously and/or partially around second fixation element 94 and thefirst anchor longitudinal axis LA_(FA). One or more of the projection140 may have a semi-circular outer surface 142, though othercross-sections are possible.

Referring now to FIG. 15, another implant assembly 10 e is generallyillustrated. The first fixation element 32 (e.g., but not limited to,the implant fixation recess 34 of the implant body 22) includes at leastone sidewall fixation feature 130 which is configured to mate andcooperate with the at least one sidewall fixation feature 108 of thesecond fixation element 94 of first anchor 92 to form a positivemechanical engagement connection against separation of the implant body22 from the first anchor 92.

More particularly, as shown, the at least one sidewall fixation feature130 of the first fixation element 32 comprises an (undercut) indentation146 in sidewall 54 of implant fixation recess 34 which mates andcooperates with projection 140 to form the positive mechanicalengagement connection. As such, the indentation 146 in sidewall 54 offirst fixation element 32 may be formed with a semi-circular surface 148which extends continuously and/or partially around the sidewall 54 ofimplant fixation recess 34 and the first anchor longitudinal axisLA_(FA).

For implant assembly 10 e, when the second fixation element 94 of firstanchor 92 is fully inserted into first fixation element 32 of implantbody 22, the sidewall fixation feature 108 of the second fixationelement 94 (and more particularly projection 140) engages with thesidewall fixation feature 130 of the implant body 22 (and moreparticularly indentation 146) to form a positive mechanical engagementconnection.

Unlike the prior embodiments, in which the second fixation element 94 offirst anchor 92 mechanically connects with the first fixation element 32particularly by a friction fit connection, with the present embodimentthe second fixation element 94 of first anchor 92 may mechanicallyconnect with the first fixation element 32 solely by a positivemechanical engagement connection within implant fixation recess 34 ofthe implant body 22.

Referring now to FIG. 16, it may be appreciated that any embodiment ofan implant assembly consistent with the present disclosure may eliminatethe second elongated anchor 80.

Referring now to FIG. 17, for implant assembly 10 g the beveledsurrounding support region 28 of the implant body 22 disposed adjacentarticulation support region 27 and the perimeter of the load bearingsurface 26 may be thickened in local areas 28 a relative to otheradjacent areas of the implant body 22 and support region 28 to providelocalized support for a glenoid rim fracture, particularly where aportion of the glenoid rim may be actually broken off from the scapula,such as may occur with an anterior or posterior dislocation. In suchinstance, support region 28 the implant body 22 may be thickenedlocalized areas 28 a which correspond to anterior and/or posteriorglenoid rim fractures.

As noted herein, the first and the second fixation elements 32, 94forming the connection between the implant 20 and the anchor 94 may bereversed. In other words, the first fixation element 32 of the implant20 (which is generally illustrated in the figures as comprising atapered recess 34) may be formed as a tapered protrusion, while thesecond fixation element 94 of anchor 92 (which is generally illustratedas a tapered protrusion) may be formed as a tapered recess.

It should also be appreciated that any embodiment of the first and/orsecond fixation elements 32, 94 may have an overall contour (includingany barbs, undercuts, or the like) which substantially correspond toeach other. As such, a single anchor 92 consistent with the presentdisclosure may be used (with and form a secure connection with) anyimplant 20 described herein, and any implant 20 consistent with thepresent disclosure may be used with (and form a secure connection with)any anchor described herein.

Any embodiment of the anchor 94 disclosed herein may optionally includea cannulated passageway 40, for example as generally illustrated in FIG.3. The cannulated passageway 40 may be configured to be advanced over aguide wire (not shown) extending outwardly from the excision site in thebone as generally described in U.S. Pat. Nos. 6,520,964, 6,610,067,6,679,917, and 7,678,151, all of which are fully incorporated herein byreference. The use of a cannulated passageway 40 and the guide wire mayfacilitate alignment of the anchor 30 with respect to the excision siteand the surrounding articular surface.

According to one aspect, the present disclosure may feature an implantassembly comprising an implant and an anchor. The implant may have aload bearing surface with a contour corresponding to a patient'sarticular surface, and a bone facing surface including a first fixationelement. The anchor may be configured to be secured to bone beneath thepatient's articular surface, and may include a second fixation element.The first fixation element is configured to be secured to the secondfixation element.

It may be appreciated that the present disclosure is not limited in itsapplication to the details of construction and the arrangement ofcomponents set forth in the following description or illustrated in thedrawings. The invention(s) herein may be capable of other embodimentsand of being practiced or being carried out in various ways. Also, itmay be appreciated that the phraseology and terminology used herein isfor the purpose of description and should not be regarded as limiting assuch may be understood by one of skill in the art.

Throughout the present description, like reference numerals and lettersindicate corresponding structure throughout the several views, and suchcorresponding structure need not be separately discussed. Furthermore,any particular feature(s) of a particular exemplary embodiment may beequally applied to any other exemplary embodiment(s) of this disclosureas suitable. In other words, features between the various exemplaryembodiments described herein are interchangeable as suitable, and notexclusive.

While a preferred embodiment of the present invention(s) has beendescribed, it should be understood that various changes, adaptations andmodifications can be made therein without departing from the spirit ofthe invention(s) and the scope of the appended claims. The scope of theinvention(s) should, therefore, be determined not with reference to theabove description, but instead should be determined with reference tothe appended claims along with their full scope of equivalents.Furthermore, it should be understood that the appended claims do notnecessarily comprise the broadest scope of the invention(s) which theapplicant is entitled to claim, or the only manner(s) in which theinvention(s) may be claimed, or that all recited features are necessary.

What is claimed is:
 1. An implant assembly comprising: an implantincluding: an implant body having a load bearing surface with a contourcorresponding to a patient's articular surface, a bone facing surface, afixation ring extending outward generally below said bone facingsurface, and at least one recess extending at least partially around anouter perimeter of the fixation ring, wherein said load bearing surfacecomprises a plastic composition or a metal composition; and an implantfixation member comprising at least one fastener segment configured tosnap into said at least one recess to couple said implant fixationmember to said implant body, said implant fixation member furtherincluding a first fixation element comprising either a plasticcomposition or a metal composition; an anchor configured to be securedto bone beneath said patient's articular surface, said anchor includinga second fixation element; and wherein said first fixation element isconfigured to be secured to said second fixation element; and whereinwhen said first fixation element comprises said plastic composition,said second fixation element comprises a plastic composition and saidload bearing surface comprise a metal composition; or wherein when saidfirst fixation element comprises said metal composition, said secondfixation element comprises a metal composition and said load bearingsurface comprise a plastic composition.
 2. The implant assembly of claim1, wherein: said load bearing surface of implant comprises said plasticcomposition; and said first fixation element comprises said metalcomposition and said second fixation element comprises said metalcomposition.
 3. The implant assembly of claim 1, wherein: said loadbearing surface of said implant comprises said metal composition; andsaid first fixation element comprises said plastic composition and saidsecond fixation element comprises said plastic composition.
 4. Theimplant assembly of claim 1, wherein: said first fixation element andsaid second fixation element are configured to mechanically connect witheach other to form a mechanical connection therebetween.
 5. The implantassembly of claim 4, wherein: said first fixation element and saidsecond fixation element are further configured to frictionally engagewith each other to form a frictional connection therebetween.
 6. Theimplant assembly of claim 5, wherein: said first fixation elementincludes a tapered portion and said second fixation element includes atapered portion; and said tapered portions are configured tofrictionally engage with each other to form said friction connectiontherebetween.
 7. The implant assembly of claim 5, wherein: said firstfixation element comprises a tapered recess; and said second fixationelement comprises a tapered protrusion.
 8. The implant assembly of claim5, wherein: said first fixation element comprises a tapered protrusion;and said second fixation element comprises a tapered recess.
 9. Theimplant assembly of claim 5, wherein: one of said first fixation elementor said second fixation element comprises a protrusion having aprotrusion sidewall; and said protrusion sidewall includes at least oneprotrusion sidewall fixation feature.
 10. The implant assembly of claim9, wherein: said at least one protrusion sidewall fixation featurecomprises at least one barb.
 11. The implant assembly of claim 10,wherein: said at least one barb comprises at least one barb ring whichextends around a circumference of said protrusion.
 12. The implantassembly of claim 11, wherein: said at least one barb ring extendscontinuously around said circumference of said protrusion.
 13. Theimplant assembly of claim 11, wherein: said at least one barb ringcomprises a plurality of barb ring segments which extend around saidcircumference of said protrusion.
 14. The implant assembly of claim 11,wherein: said at least one barb comprises at least two barb rings whichextends around a circumference of said protrusion.
 15. The implantassembly of claim 14, wherein: each of said at least two barb ringscomprises a plurality of barb ring segments which extend around saidcircumference of said protrusion; and said plurality of barb ringsegments of each of said at least two barb rings are laterally offsetrelative to one another around said circumference of said protrusion.16. The implant assembly of claim 9, wherein: said at least oneprotrusion sidewall fixation feature comprises at least one rib.
 17. Theimplant assembly of claim 16, wherein: said at least one rib comprises aplurality of ribs.
 18. The implant assembly of claim 17, wherein: saidplurality of ribs extend substantially longitudinally along alongitudinal length of said protrusion.
 19. The implant assembly ofclaim 17, wherein: said plurality of ribs are substantially equallyspaced around a circumference of said protrusion.
 20. The implantassembly of claim 17, wherein: said plurality of ribs are substantiallyparallel to each other.
 21. The implant assembly of claim 4, wherein:said first fixation element and said second fixation element are furtherconfigured to mechanically interlock with each other to form a positivemechanical engagement therebetween.
 22. The implant assembly of claim21, wherein: said first fixation element comprises a tapered recess andwherein said second fixation element comprises a tapered protrusion. 23.The implant assembly of claim 21, wherein: said first fixation elementcomprises a tapered protrusion and wherein said second fixation elementcomprises a tapered recess.
 24. The implant assembly of claim 21,wherein: one of said first fixation element or said second fixationelement comprises a protrusion having a protrusion sidewall; and saidprotrusion sidewall includes at least one protrusion sidewall fixationfeature; and said other of said first fixation element or said secondfixation element comprises a recess having a recess sidewall; and saidrecess sidewall includes at least one recess sidewall retention feature.25. The implant assembly of claim 24, wherein: said at least oneprotrusion sidewall fixation feature is configured to mate with said atleast one recess sidewall fixation feature to form said mechanicalinterlock.
 26. The implant assembly of claim 24, wherein: said at leastone protrusion sidewall fixation feature comprises at least one barb;said at least one recess sidewall fixation feature comprises at leastone ridge; and said at least one barb is configured to cooperate withsaid at least one ridge to form said mechanical interlock.
 27. Theimplant assembly of claim 24, wherein: said at least one protrusionsidewall fixation feature comprises at least one projection; and said atleast one recess sidewall fixation feature comprises at least oneindentation; and said at least one projection is configured to mate withsaid at least one indentation to form said mechanical interlock.
 28. Theimplant assembly of claim 1, wherein: at least a portion of said anchorincludes a threaded portion configured to engage said bone.
 29. Theimplant assembly of claim 1, wherein: said implant is a synovial jointimplant.
 30. The implant assembly of claim 1, wherein: said implant is aball and socket joint implant.
 31. The implant assembly of claim 1,wherein: said implant is a shoulder joint implant.
 32. The implantassembly of claim 1, wherein said first fixation element and said secondfixation element form a Morse tapered connection.
 33. The implantassembly of claim 1, wherein said at least one recess extendscontinuously around the perimeter of the fixation ring.